The present invention relates to improvements in adhesive-coated tapes.
The present invention further relates to improved adhesive-coated thermoplastic tapes.
The present invention more particularly relates to adhesive-coated thermoplastic tapes having improved hand tearability characteristics.
The present invention most particularly relates to adhesive-coated thermoplastic tapes that are both perforated and embossed for improved hand tearability.
It is often necessary for adhesive-coated tapes that are designed for such purposes as packaging, sealing, or similar purposes, to possess a high tensile strength. For this, and other reasons, thermoplastic film, reinforced cloth and/or paper, having a high tensile strength, have been used frequently as the substrate materials in prior art adhesive-coated tapes.
Due to the requisite high tensile strength of the thermoplastic film substrate material, cutting implements such as knives, scissors or tape dispensers, have been necessarily employed to remove sections of an adhesive-coated thermoplastic film tape from a storage roll during use. The requirement of a cutting implement when using prior art thermoplastic film adhesive-coated tapes makes their use in packaging, sealing, etc. also quite inconvenient and inefficient.
Additionally, the majority of adhesive-coated thermoplastic polymer tape webs possess a longitudinally-oriented molecular configuration. Hand tearing of most thermoplastic tapes of the prior art is thus a very difficult operation to perform. In fact, attempts at transverse hand tearing of these thermoplastic film prior art tapes results generally in undesirable adhesive tape stretching in the longitudinal direction, with a generally unattachable and distorted tape edge.
The present invention provides ready, easy hand-tearability of an adhesive-coated thermoplastic polymer tape by providing a plurality of "oriented" discrete perforations incorporated within the thermoplastic film substrate, along with an overlaid pattern of embossing of the non-adhesive-coated surface of the thermoplastic film substrate.
The above-described configuration allows for instant, highly efficient hand tearability at any point of the adhesive-coated thermoplastic tape. In fact, the tear edge can be oriented linearly at any angle, or arcuately or stepped, if desired.
An important characteristic of a thermoplastic adhesive-coated tape for certain applications is the low degree of water vapor permeability or moisture porosity, when the tape is used in certain protective sealing applications. The instant invention adhesive-coated thermoplastic perforated and embossed tape exhibits a very low level of water vapor permeability. This is due primarily to the unique, very thin discrete perforations, which essentially "self seal" following their formation. Another factor of importance in this regard, (i.e., reduced water vapor permeability), is the presence of a highly water vapor impermeable adhesive coating applied to the rear surface of the thermoplastic film substrate. This adhesive coating thus also aids in the moisture sealing effect exhibited by the plurality of discrete perforated, but apposed regions.